Option Greeks: 4 Factors for Measuring Risk

6 mins read
by Angel One

The price of an option can be influenced by various factors, which might work in traders’ favour or against them depending on the position they have taken. Successful traders are aware of the factors that affect option pricing, including the so-called “Greeks”—a group of risk measures named after the Greek letters that denote them, which indicate how sensitive an option is to time value decay, changes in implied volatility, and changes in the price of its underlying security.

Theta, Vega, Delta, and Gamma are the four fundamental Greek risk indicators associated with options.

Recognize Options Contracts

Contracts for difference are used to hedge a portfolio. The objective is to counterbalance any adverse movements in other investments. Additionally, options contracts are used to speculate on whether the price of an asset will rise or decline.


It refers to the amount by which an option’s premium, or market value, swings in the run-up to expiration. Price changes can be triggered by various variables, including the company’s financial health, economic conditions, geopolitical threats, and market movements in general.

Investors use implied volatility, abbreviated as implied vol, to foresee or forecast future movements in the underlying security or stock, as well as the option’s price. Implied volatility reflects the market’s assessment of the probability that the price of an asset will move. If implied volatility is predicted to increase, the premium on an option is likely to increase as well.


Table 4 summarises the Greeks’ four key risk indicators that a trader should examine before initiating an option transaction.

The principal Greeks

Vega quantifies The Effects of a Volatility Change.

Theta quantifies The Effect of a Time Remaining Delta Measurement Change The Effect of a Change in the Underlying Gamma Price quantifies the rate of change of Delta.


Delta is the variation in the price of an option (or, more precisely, the premium of an option) because of a change in the underlying asset. The value of Delta is between -100 and 100 for puts and between 0 and 100 for calls (-1.00 to 1.00 without a shift in the decimal, respectively). 3 Puts generate negative Delta because they are inversely related to the underlying asset—put premiums reduce when the underlying security increases, and vice versa.

In contrast, call options positively correlate with the underlying asset’s price. If the cost of the underlying asset rises, then the call premium increases as well, assuming that no other variables such as implied volatility or time remaining until expiration change. If the underlying asset’s price declines, the call premium will similarly fall, assuming that all other variables remain constant.

Three points to bear in mind when dealing with Delta:

1) Delta tends to increase closer to expiration for near- or at-the-money options.

2) Gamma, a measure of Delta’s rate of change, is used to assess Delta further.

3) Delta can also alter in response to variations in implied volatility.


Gamma quantifies the pace at which Delta changes over time. Because delta values fluctuate in lockstep with the underlying asset’s price, Gamma is used to quantify the rate of change & provide traders with an indication of what to expect in the future. Gamma values are greatest for options in the money and lowest for those that are deep in- or out-of-the-money.

While Delta varies with the underlying asset price, Gamma is a constant that represents the pace at which Delta changes. Gamma is, therefore, beneficial for measuring the stability of Delta, which may be used to calculate the probability of an option hitting the strike price at expiration.

Gamma can be thought to measure an option’s probability’s stability. If Delta is the likelihood of being in the money at expiration, Gamma is the probability of that probability remaining stable over time.

There are a few other considerations to consider regarding Gamma:

1) For deep out-of-the-money and deep-in-the-money options, Gamma is the smallest.

2) Gamma is most significant as the choice approaches money.

3) Gamma is more significant than zero for extended options and less than zero for short options.


Theta quantifies the pace at which an option’s value or premium depreciates over time. Time decay is the gradual deterioration of an option’s value or price over time. With time, the probability of an option being lucrative or in the money decreases. Time decay accelerates when an option’s expiration date approaches, as there is less time remaining to profit from the trade. 6

Because time travels in the same direction, theta is always negative for a single option. Once a trader purchases an option, the clock begins ticking, and the option’s value instantly begins to depreciate until it expires worthless on the predefined expiration date.

Values of Theta are always negative for extended options & will always equal zero at expiration, as time only flows in one direction and time expires when an option expires.

Several other factors about theta to consider when trading include the following:

1) Theta values for out-of-the-money options might be high if they have high implied volatility.

2) Theta is often most prominent for at-the-money options due to the shorter time required to profit from an underlying price movement.

3) Theta will climb significantly as time decay increases in the final weeks before expiration, severely undermining the position of a long option holder, especially if implied volatility drops concurrently.


Vega quantifies the risk associated with changes in implied volatility or the anticipated forward-looking volatility of the underlying asset price. While Delta is concerned with current price movements, Vega is concerned with changes in implied future volatility.

Consider the following points regarding Vega:

1) Due to changes in implied volatility, Vega might increase or decrease independently of the underlying asset’s price.

2) Vega may rise in response to rapid changes in the underlying asset.

3) Vega decreases as the option approaches expiration.

The Verdict

The Greeks aid in quantifying the risks and potential profits associated with an option investment. It is insufficient to understand the entire amount at risk in an option position. It is critical to understand the chance of a trade making money to calculate a range of risk-exposure assessments. Once one has a proper grasp of the fundamentals, one may begin applying them to your current strategies.

This article should give you a good idea about 4 factors for measuring risk and option greeks risk factor